Frictionless loading method and apparatus



Aug. 16, 1966 w. M COWN, JR 3,266,531.

FRICTIONLESS LOADING METHOD AND APPARATUS Filed March 25, 1964 5Sheets-Sheet l I A l" M/VE/VTQ/P JAMES W. Me COWN, JR.

ATTORNEY Aug. 16, 1966 w ccow JR FRICTIONLESS LOADING METHOD ANDAPPARATUS Filed March 25, 1964 5 Sheets-Sheet 2 lA/VE/VTOR JAMES 14McC'OW/V. JR.

MMW

ATTOR/VEV Aug. 16, 1966 J. w. M COWN, JR

FRICTIONLESS LOADING METHOD AND APPARATUS Filed March 25, 1964 5Sheets-Sheet 3 TIMER LOADEI? CIRCUIT COMPENSAT/A/G C/RCU/T ATTORNEY3,256,531 FRIIITIGNLESS LGADING lt IETI-IUD AND APPARATUS Barnes W.hIcCown, .Iiz, Iexarirana, Tern, assignor to Day & Zimmermann, Inc,Ihiiadelphia, Pa, a corporation of Maryiand Filed Mar. 25, 1964, Ser.No. 354,539 15 Ciairns. (@l. 141-1) This invention relates to acompensating frictionless loading apparatus, and more particularly, to aloading apparatus for explosives in powder or liquid form.

I-Ieretofore, all of the explosive powder loaders that I am familiarwith were provided with frictional inducing surfaces, pinch points,unavoidable pressures, etc. Such loaders are inherently hazardous,especially when the powder is sensitive, such as lead azide, RDX, etc.The present invention provides a frictionless loader in the sense thatthere are no frictional inducing surfaces or pinch points to create ahazard and a potential explosion during loading operations.

When the powder to be loaded is disposed in a hopper, there wiil bebridging over of the powder in the throat of the hopper when flow isshut off. Whenever any means is provided to shut off the flow, such as avalve or the like, there is created a friction or pinch point which is apotential hazard. To overcome this objectionable feature, the presentinvention provides a hopper wherein the powder is permitted to freelyflow therefrom without interruption. In a given length of time, a givenamount of powder will have been discharged from the hopper into areceptacle. A control means is provided to intermittently interrupt thedischarge of the flow of powder into the receptacle and divert the sameto a return means which returns the powder back into the hopper. Byreturning the powder back into the hopper, the additional benefit ofreblending of the powder is obtained.

The loader is adapted to be utilized in conjunction with anyconventional loading press having a loading ram for compacting thepowder in its receptacle. A timing means is provided so that theinterruption or diversion of the flow from the hopper is effected intimed relationship with respect to the placing of a receptacle toreceive powder from the hopper and the stroke of the loading ram. Thus,a change will be necessitated in the timing of the diversion of powderfrom the hopper as dictated by the height of compressed powder in thereceptacle. If the compressed height of powder in the receptacle isWithin normal tolerances, no changes are effected by the timing means.If the height of the compressed powder is above or below an acceptablelevel, a change is effected in the timing means to compensate for thehigh or low levels detected.

It is an object of the present invention to provide a novel loadingapparatus.

It is another object of the present invention to provide a novel loadingapparatus for powdered material.

It is another object of the present invention to provide a novelapparatus and method for loading powder explosives.

It is another object of the present invention to provide an explosiveloading apparatus wherein powdered explosive is continuously dischargedfrom a hopper and reblending of powder is attained by recirculating aportion of the discharged powder back into the hopper.

It is another object of the present invention to provide a loadingapparatus having structure for synchronizing operation of the apparatusin conjunction with the detection of acceptable production at aconsolidating station of the powder.

It is another object of the present invention to provide a novel loadingmethod.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there are shown in thedrawings forms which are presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIGURE 1 is a front elevation view of loading apparatus in accordancewith the present invention, with parts broken away for clarity ofillustration.

FIGURE 2 is a sectional view taken along the line 22 in FIGURE 1.

FIGURE 3 is a sectional view taken along the line 33 in FIGURE 2.

FIGURE 4 is a sectional view taken along the line 44 in FIGURE 1.

FIGURE 5 is a sectional view taken along the line 55 in FIGURE 4.

FIGURE 6 is a schematic diagram.

FIGURE 7 is a schematic wiring diagram.

Referring to the drawing in detail, wherein like numerals indicate likeelements, there is shown in FIGURE 1 a loading apparatus designatedgenerally as 10. The apparatus 10 is disposed within a metallic housing12 which is open at its top to atmosphere at a point above the roof ofthe building. Hence, any explosions within the housing 12 will bedirectly channeled upwardly through the roof of the building to theatmosphere. The housing 12 is provided with a selectively operable door14- in any convenient manner.

Within housing 12, there is provided a horizontally disposed base plate16. Base plate 16 supports a mounting plate 18. As shown more clearly inFIGURE 3, a mounting block 20 is provided on the plate 18 and adjustablypositionable with respect thereto by means of the slotted openingthrough which threaded bolt 22 is secured.

A support member 24 is pivotably secured to the block 20 for pivotablemovement about the longitudinal axis of pin 26. Support member 24 isprovided with an upstanding wall 28 having an aperture therethrough. Amounting ring 30 is secured to the upper end of wall 28 in anyconvenient manner.

The mounting ring 30 is provided with a flat upper surface and a taperedaperture extending therethrough. Ring 30 receives and supports a hopper32. Hopper 32 is conical and is provided with a controlled dimension atits throat 33. The flow passage below the throat 33 tapers radiallyoutwardly on the hopper 32. It is within the scope of the presentinvention to provide a removable disk at the throat 33. A plurality ofsuch disks may be utilized with different sized holes therethrough. Whenpouring explosives, it is advisable to substitute an entirely new hopperwhen changing from one explosive to another.

A funnel 34 is disposed below and spaced from the lower end of thehopper 32. Funnel 34- is provided with a reduced diameter portion whichis disposed within the aperture 36 in the plate 18. A U-shaped notch isprovided in one wall of funnel 34 for a purpose to be describedhereinafter.

The mounting ring 30 is provided with a flange 38. A power cylinder isremovably coupled to the flange 38 by means of bracket 39. A motivefluid, such as air, is capable of being introduced into the cylinder 40by way of conduit 42. A piston is disposed within the cylinder 40 andadapted to be biased by the motive fluid downwardly and to the left inFIGURE 3. During such movement of the piston, spring 41 is compressed.When the pressure of the motive fluid is relieved, the spring 41 expandsand returns the piston to its initial position.

A piston rod 44 is connected to the piston disposed within cylinder 4G.The end of piston rod 44 remote from the piston is movably andadjustably coupled to a shuttle 46. The shuttle 46 is U-shaped intransverse cross section as shown more clearly in FIGURE 2. The shuttle46 is provided with an aperture 48 which is in line with the throat 33in the discharging position of the shuttle 46. Thus, in this position ofthe shuttle 46, powder will be discharged from the throat 33 directlythrough the aperture 48 and through the funnel 34.

A recirculating means generally designated as 50 is provided to receivepowder diverted by the shuttle 46 and return the same to the hopper 32thereby effecting a reblending of the powder. Such recirculating meansincludes wheel 52 in the general form of a truncated cone. Wheel 52 hasa rim 54 defined by an axially extending Wall and radially inwardlydirected parallel walls, one of which terminates in a radially inwardlytapered tip 58. Within the rim 54, there are provided a plurality ofpockets 56. As shown more clearly in FIGURES 2 and 3, the rim 54 is ofsuch a size and is positioned in a manner so that it may receive powderfrom the shuttle 46 and convey the same through an arc of approximately180 degrees at which point the powder collected will be returned intothe hopper 32.

The wheel 52 is provided with a hub 60. Hub 60 is removably coupled toone end of shaft 62. Shaft 62 extends through opposite walls of ahousing 66. A gear 64 is secured to the shaft 62 and is in meshingengagement with a worm 72. Worm 72 is tangent to the gear 64 andconnected to one end of a pneumatically rotated shaft.

The housing 66 is connected by flanges and bolts to a standard 68.Standard 68 is provided at its lower end with a base 70 removablycoupled to the mounting plate 18. At its upper end, the standard 68 isprovided with a plate 73 which has an aperture through which the shaftfor the worm 72 extends. Said last-mentioned shaft extends into apneumatic motor 74. Said shaft is in effect the output shaft fortransmitting rotary motion from the motor 74. A hydraulic or electricmotor could be used in lieu of the pneumatic motor 74 if desired.

As shown more clearly in FIGURE 1, a support plate 76 is supported bythe housing 12 below the base plate 16. A table 78 is rotatablysupported by hearings on the plate 76 and coupled to a gear reducer 82of the motor 80. Motor 80 rotatably drives the table 78 tointermittently position a primer cup 79 or the like below an aperture inthe plate 16 which in turn is in line with and below the reduceddiameter portion of the funnel 34. The table 78 may be provided withpockets into which the primer cups are disposed.

As shown more clearly in FIGURES 1, 4 and 5, a timer housing 84 isprovided. Housing 84 is provided with a removable cover 86 having atransparent window 88 therein. A partition 90 is removably supportedwithin the housing 84 by means of brackets. A shaft 87 extends throughthe partition 90 and has a gear 89 coupled to one end thereof betweenthe partition 90 and the cover 86.

A portion of the high and low compensating circuits are adapted tocooperate with the gear 89 to rotate the same incremental amounts inopposite directions. Such portions are identical. Accordingly, only theportion of the high compensating circuit will be described in detailwith corresponding primed numerals provided for the correspondingstructure of the low compensating circuit.

A pawl 91 is supported for contact with the gear 89 to rotate the samein a counterclockwise direction in FIGURE 4. Pawl 91 is supported bypiston rod 92 which extends through a bushing 95. Piston rod 92 iscoupled to a piston within cylinder 93. The last-mentioned piston isspring biased upwardly in FIGURE 4. A motive fluid, such as air, may beintroduced through conduit 94 to bias the piston downwardly against thespring pressure to move the pawl 91 into contact with the gear 89. Asingle action solenoid may be used in lieu of the air operated cylinder93. An adjustable limit stop 96 is provided on the partition to limitthe stroke of the piston rod 92.

The shaft 87 is an integral part of an adjustable potentiometer 98supported by the shaft 87 on the opposite side of the partition 90 fromthe gear 89. Within the housing 84 to the left of the partition 90 inFIGURE 5, there will be housed numerous components of an electricalcircuit including relays, switches, and the like which will be describedhereinafter.

In FIGURE 6, there is illustrated a compensating circuit 99 and a loadercircuit 100 in diagrammatic form. Circuit 99 includes microswitches 108and 110. Switch 108 will be actuated by the consolidating ram of thepress for compacting the powder within the primer cup 79. Switch 108 isadapted to be actuated when the amount of powder within the cup 79 is inexcess of a permissible limit or range. Switch 108 is coupled to asolenoid 104 which controls a valve in the conduit 94.

When solenoid 104 is actuated, air or other motive fluid will flowthrough conduit 94 into cylinder 93 to effect rotation of the gear 89 ina counterclockwise direction in FIGURE 4 to thereby adjust thepotentiometer 98 in one direction. A low limit microswitch 110 isadapted to be actuated when the compressed powder is below thepermissible limit or range. In a similar manner, switch 110 will operatesolenoid 106 which will control the flow of air or other motive fluidthrough conduit 94 to effect rotation of the gear 89 in a clockwisedirection in FIGURE 4 to thereby adjust the potentiometer 98 in anopposite direction.

The contact terminals of the potentiometer 98 are coupled to a solidstate timer 148. When actuated, timer 148 operates relay 102 which inturn controls activation of solenoid 116. Solenoid 116 controls the flowof air or other motive fluid through conduit 42 to effect movement ofthe shuttle 46 against the pressure of spring 41. In FIGURE 6, the wheel52 and hopper 32 are diagrammatically illustrated.

In FIGURE 7, there is illustrated a schematic Wiring diagram. A load iscoupled by Way of conductors 118 and 120 to the terminals of a source ofelectrical power such as a volt A.C. 60 cylce single phase source.Conductor 118 is provided with an on-off switch 124. Conductor 126extends between the conductors 118 and and contains a high manualnormally open switch 128 and the solenoid 104. Conductor 130 extendsfrom conductor 118 to a terminal for switch 108.

A manual normally open switch 134 is provided in conductor 136 coupledacross conductors 118 and 120. Conductor 136 contains solenoid 106. Aswitch 110 is coupled across conductors 130 and 136. Switch 110 is amicroswitch responsive to a low charge in the receptacle such as aprimer cup.

A conductor 138 is coupled across conductors 118 and 120 and containssolenoid 116, the switch 140 operated by a solenoid 102, and switch 142.Switch 142 is one-half of a double pole switch of which switch 114 isthe other half. A solid state timer 148 is coupled across the conductors118 and 120 by conductors 144 and 146, connected respectively to thecontacts 2 and 3 on the timer 148. It will be noted that thepotentiometer 98 is coupled across contacts 4 and 5 on the timer 148.The solenoids 104 and 106 are coupled to the pointer of thepotentiometer 98 to increase or decrease the resistance between contacts4 and 5 as alluded to above and as will be explained hereinafter. Switch114 is coupled across contacts 7 and 8 of the timer 148. The solenoid102 is coupled across the contacts 1 and 9 of the timer 148.

In the timer 148, contacts 3 and 4 are coupled together, contacts 4 and7 are coupled together, contacts 8 and 9 are coupled together, andcontacts 1 and 3 are coupled together.

Operation of the structure described heretofore, assuming switch 124 isclosed and wheel 52 is rotating, is as follows:

Powder is continuously permitted to discharge through the throat of thehopper 32. With the shuttle 46 in the position illustrated in FIGURE 3,such powder passes through the aperture 48, through the funnel 34,through the aperture in plate 16 into a receptacle such as a detonatoror primer cup 79 disposed therebelo'w. After a predetermined interval oftime, timer 148 times out whereby solenoid 102 is energized to openswitch 140 thereby deenergiz'ng solenoid 116.

When solenoid 116 is deenergized, the pressure of the motive fluid onthe piston in cylinder 40 is removed whereby the spring 41 expands andmoves the shuttle 46 to an inoperative position. In the inoperativeposition of the shuttle 46, the aperture 48 is to the right of astraight line extending from the throat 33 to the aperture 36. Hence,all powder discharged from the throat 33 into the shuttle 46 will betransferred by gravity into one of the pockets 56 on the continuouslyrotating wheel 52. Thereafter, such powder will be discharged from itsrespective pocket back into the hopper 32. The amount of powder whichflows from the throat 33 through the aperture 48 is a function of timesince the flow rate is continuous. As soon as the next cup 79 ispositioned to receive powder, switches 114 and 142 will have beenmechanically actuated to a closed position by an element of the loadingpress. For example, on a Jones loading press, such element may be a partof the Geneva movement device. Since switch 140 is normally closed,solenoid 116 will be energized. When solenoid 116 is energized, thevalve controlling flow in conduit 42 will be open whereby motive fluidsuch as air will be introduced into cylinder 40 to reciprocate shuttle46 to the position illustrated in FIGURE 3.

Immediately following the station where an increment of powder isdispensed as described above, there is a press consolidating stationwherein the powder is consolidated to a required pressure. At thisstation, there is provided high limit microswitch 108 and low limitmicroswitch 110 which are actuated by the consolidating ram when thecompressed powder height is outside of a predetermined range. As long asthe compressed powder height is maintained within a predetermined range,acceptable production is being accomplished and neither switch 108 nor110 is activated. If the compressed powder height is so high as to beoutside the acceptable range, switch 108 is activated to effectenergization of solenoid 104.

When solenoid 104 is energized, motive fluid such as air is permitted toflow through conduit 94 into cylinder 93 to move the piston rod 92 andpawl 91 downwardly in FIGURE 4. Such downward movement of the pawl 91rotates the gear 82 in a counterclockwise direction in FIGURE 4 therebydecreasing the resistance in the potentiometer 98. Such decrease in theresistance of potentiometer 98 dezrea es the time interval for theenergization of solenoid 116 which in turn decreases the time intervalwherein the shuttle 46 is in the position shown in FIGURE 3. As a resultthereof, the amount of powder discharged into the primer cup isdecreased.

If the compressed powder height is below the predetermined range, switch110 will be activated which in turn will energize solenoid 106. Solenoid106 controls the flow of motive fluid in conduit 94 which in turn caneffectuate rotation of the gear 89 in a clockwise direction in FIGURE 4.Rotation of gear 89 in a clockwise direction in FIGURE 4 results in anincrease in the resistance of potentIometer 98 thereby increasing thetime interval for energization of solenoid 116. Thus, it will be seenthat energization of the switches 108 and 110 have opposite effects onthe amount of powder discharged through funnel 34 into a receptacle suchas a primer 6 cup 79 and compensate for the compressed powder height atthe loading press consolidating station.

Solenoid 104 may be energized at any desirable time by manually closingswitch 128. Likewise, solenoid 106 may be energized at any time byclosing switch 134. Manual switches 128 and 134 may be energized at anytime When it is desired to move the timer 148 to mid range should thecompressed powder heights crowd too close to the limits of thepredetermined range while still indicating acceptable production.

On tests conducted heretofore, consistency within two three milligramswas attained. Compensation can be controlled within two milligrams orcloser by adjusting the limit stops 96 and 96'. When converting fromloading of one type of powder to another, the only changes required arechanges to the throat size in the hopper 32 or replacement of the entirehopper when loading explosives. Through experiments, it has been foundthat the diameter of the throat 33 should be .062 inch minimum for leadazide, 0.78 inch minimum for delay powder, and .102 inch minimum forRDX. The hopper 32 and shuttle 46 are preferably made from stainlesssteel type 304. All other components may be made of mild steel andchromeplated (.001.002 inch) except standard 68 which may be aluminumchannel and plate. Other materials may be substituted as desired to suitthe users need.

If desired, a manually operated switch 150 may be provided at a remotepoint. When it is desired to empty the loader of explosive powder, areceptacle may be placed below the funnel 34 and switch 150 activated toenergize solenoid116. When all of the powder has been discharged fromthe hopper 32 into the receptacle, switch 150 will be opened. Wheneverthe loading apparatus is not in use, switch 124 should be in an openposition. Also, the hopper 32 and related elements should be in thephantom position illustrated in FIGURE 3. The provision for meansenabling the hopper to be rotated to the inoperative position shown inphantom in FIGURE 3 facilitates cleaning and removal of the hopper 32and provides for easy access to the funnel 34. The U-shaped notch 35enables the shuttle 46 to rotate to the phantom position in FIGURE 3.

While the above description is set forth in connection with an explosivepowder, it is within the scope of the present invention to utilize theloading apparatus in connection with other types of powders and in otherindustries such as the pharmaceutical industry. While the descriptionset forth above is described in connection with the use of powder in thehopper 32, obviously the apparatus may be utilized in conjunction with aliquid.

In case of an electrical power failure, the pneumatic motor 74 willcontinue to rotate wheel 52 thereby recirculating powder back into thehopper to avoid powder spillage. Each of the cylinders 40, 93 and 93 areoneway cylinders with spring return on their pistons so that theassociated piston rods will be biased to an inactive position if thereis a failure of the air pressure.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

I claim:

1. Loading apparatus comprising a hopper, a shuttle means below saidhopper, said shuttle means having a first position for enabling powderfrom said hopper to be discharged into a receiving receptacle, saidshuttle means having a second position wherein said shuttle meansdirects powder discharged from said hopper to a recirculating meanswhich returns such powder to the hopper, and means for selectivelycontrolling the movement of said shuttle means between said first andsecond positions.

2. Apparatus in accordance with claim 1 wherein said last-mentionedmeans includes a motor means for moving said shuttle means to its firstposition and a spring for moving said shuttle means to its secondposition.

3. Apparatus in accordance with claim 1 wherein said recirculating meansincludes a device mounted for rotation through a closed loop, saiddevice including pockets for receiving powder directed thereinto fromsaid shuttle means, and said device being adapted to discharge anypowder in the pockets into the hopper.

4. Apparatus in accordance with claim 1 wherein said last-mentionedmeans includes compensating structure for adjusting the time interval atwhich said shuttle means is in its first position as a function of theamount of powder compressed at a subsequent compacting station.

5. Apparatus in accordance with claim 1 wherein said last-mentionedmeans includes an adjustable potentiometer adapted to increase ordecrease the time interval at which said shuttle means is disposed inits first position.

6. Loading apparatus comprising a hopper, said hopper having a dischargethroat which is unobscured and through which matter may be continuouslydischarged, means below said throat for selectively diverting some ofthe matter discharged through said throat, and movable mechanical meansfor receiving such diverted matter and returning the same to saidhopper.

7. Apparatus in accordance with claim 6 wherein said mechanical meansincludes a rotatable wheel within which a portion of said hopper isdisposed.

8. Apparatus in accordance with claim 6 wherein said diverting meansincludes a reciprocable shuttle having a portion disposed within theconfines of said mechanical means in one position of said shuttle.

9. Apparatus in accordance with claim 6 including a feedbackcompensating means for controlling the diverting of such matter wherebythe amount of such matter discharged from said throat and not returnedto said hopper may be controlled as to quantity by controlling the timeperiod during which diversion of such matter is not being accomplished.

10. Loading apparatus comprising a housing, a hopper within saidhousing, a reciprocable shuttle below said hopper, said hopper having adischarge throat unobscured at all times, said shuttle having anaperture adapted to be aligned with said throat in one position of saidshuttle, a wheel rotatably supported in a manner so that a portion ofsaid shuttle and hopper are within the confines of said wheel, saidwheel having pockets on its inner periphery to receive matter from saidshuttle in another position of said shuttle, a funnel below saidshuttle, and means for selectively moving said shuttle for controllingthe time period during which said shuttle aperture is in line with saidthroat.

11. Apparatus in accordance with claim 10 wherein said last-mentionedmeans includes a compensating circuit for increasing or decreasing thetime interval during which said shuttle aperture is in line with saidthroat.

12. In a method of loading a powder from a hopper into a receptaclecomprising the steps of continuously discharging powder through a throatin said hopper, collecting powder from said throat in a receptacle,diverting powder from said throat, moving the receptacle, returning thediverted powder to said hopper, ceasing the diversion of powder, andcollecting powder in another receptacle.

13. A method in accordance with claim 12 including controlling the timeinterval for said step of diverting powder in response to the amount ofpowder collected in said first receptacle.

14. A method in accordance with claim 12 wherein said step of returningthe powder to the hopper includes collecting the diverted powder on theinner periphery of a rotating wheel, and dumping the so-collected powderback into the hopper by causing the hopper to be positioned within theinner periphery of said wheel.

15. A method in accordance with claim 12 including the step ofcontrolling the period of time during which the powder is beingcollected in said other receptacle by varying the resistance of apotentiometer in a compensating circuit in response to the compressedheight of powder collected in said first-mentioned receptacle.

References Cited by the Examiner UNITED STATES PATENTS 1,394,097 10/1921 Lachapelle 222318 X 3,087,517 4/1963 Magnuson et al. 141-13,107,703 10/1963 Smith 141-129 X LAVERNE D. GEIGER, Primary Examiner.

H. BELL, Examiner.

12. IN A METHOD OF LOADING A POWDER FROM A HOPPER INTO A RECEPTACLECOMPRISING THE STEPS OF CONTINUOUSLY DISCHARGING POWDER THROUGH A THROATIN SAID HOPPER, COLLECTING POWDER FROM SAID THROAT IN A RECEPTACLE,DIVERTING POWDER FROM SAID THROAT, MOVING THE RECEPTACLE, RETURNING THEDIVERTED POWDER TO SAID HOPPER, CEASING THE DIVERSION OF POWDER, ANDCOLLECTING POWDER IN ANOTHER RECEPTACLE.